Chlorination of aluminous material at superatmospheric pressure

Abstract

Aluminous material is chlorinated in the presence of a reducing agent at pressures greater than three atmospheres. A greater than linear increase in reaction rate obtained at superatmospheric pressures is a feature of the chlorination reaction which is employed to increase aluminum chloride production rate. Choice of pressure used is governed more by mechanical limitations than by an upper limit inherent to the chemical reaction.

What is claimed is: 
     
       1. A method for chlorinating an aluminous material containing oxygen comprising chlorinating the aluminous material in the presence of a reducing agent at a pressure of greater than three atmospheres, with the aluminum chloride production rate coefficient being increased compared with what it is at pressures below three atmospheres. 
     
     
       2. The method of claim 1 wherein the pressure is at most 15 atmospheres. 
     
     
       3. The method of claim 1 wherein the aluminous material is chlorinated at a temperature of from 550° to 800° C. 
     
     
       4. The method of claim 1 wherein the reducing agent is selected from the group consisting of coke, carbon, carbon monoxide, COCl 2  and CCl 4 . 
     
     
       5. The method of claim 1 wherein the aluminous material is alumina. 
     
     
       6. A method for the chlorination of an aluminous material containing oxygen, which comprises chlorinating the aluminous material in a pressure reactor at a pressure in excess of three atmospheres at a temperature of from 550° to 800° C. in the presence of a carbonaceous reducing agent selected from the group consisting of coke, carbon, carbon monoxide, COCl 2  and CCl 4 , with the aluminum chloride production rate coefficient being increased compared with what it is at pressures below three atmospheres. 
     
     
       7. The method of claim 1 wherein the aluminous, oxygen-containing material is calcined before being chlorinated. 
     
     
       8. In a method for chlorinating an aluminum-oxygen containing material in the presence of a carbonaceous reducing agent, the improvement comprising chlorinating at a pressure greater than three atmospheres, with the aluminum chloride production rate coefficient being increased compared with what it is at pressures below three atmospheres. 
     
     
       9. The method of claim 1 wherein the pressure is between 3.3 and 4.7 atmospheres. 
     
     
       10. The method of claim 1 wherein the pressure is at least five atmospheres. 
     
     
       11. The method of claim 1 wherein the pressure is at least 15 atmospheres. 
     
     
       12. The method of claim 1 wherein the pressure is at least 10 atmospheres. 
     
     
       13. The method of claim 1 wherein the pressure is at least seven atmospheres. 
     
     
       14. The method of claim 1 wherein the pressure is at least nine atmospheres. 
     
     
       15. The method of claim 1 wherein the pressure is at least 11 atmospheres. 
     
     
       16. The method of claim 1 wherein the pressure is at least 13 atmospheres. 
     
     
       17. The method of claim 1 wherein the pressure is between 5 and 15 atmospheres. 
     
     
       18. The method of claim 1 wherein the pressure is between 5 and 10 atmospheres. 
     
     
       19. The method of claim 1 wherein the pressure is between 10 and 15 atmospheres.